Special routes of U.S. Route 81

Loop 353 is the former routing of US 81 in southern San Antonio, formed in 1961 when US 81 was rerouted onto the I-35 freeway to the east. It was originally marked as a business route of US 81.

Loop 368 is the former routing of US 81 in northern San Antonio, formed in 1962 when US 81 was rerouted onto the I-35 freeway to the east. It was originally marked as a business route of US 81.

Business U.S. Highway 81-E (Bus. US 81-E) is the former route of US 81 and US 287 through Rhome. The route was originally designated as Loop 506 on May 31, 1972, and signed as a business route of US 81 and US 287; the portion south of its intersection with Spur 440 (numbered the same day as a redesignation of SH 114 through Rhome) was also signed as a business route of SH 114.[2][3] Loop 506 was cancelled and transferred to Business US 81 on June 21, 1990.[1]

Business U.S. Highway 81-D (Bus. US 81-D) is the former route of US 81 and US 287 through Decatur. The route was originally designated as Loop 357 on April 30, 1962.[5] Loop 357 was cancelled and transferred to Business US 81 on June 21, 1990.[4]

Business U.S. Highway 81-C (Bus. US 81-C) is the former route of US 81 and US 287 through Alvord. The route was originally designated as Loop 249 on June 16, 1980.[7] Loop 249 was cancelled and transferred to Business US 81 on June 21, 1990.[6] Although not officially designated as Business US 287, the route is cosigned as such from the US 81/US 287 bypass and at the junction with FM 1655.

The southernmost Business US-81 in Oklahoma is in the town of Rush Springs, Oklahoma. It begins south of the town, following Rush Street into the central business district. In the middle of downtown Rush Springs, there is a four way stop with Blakeley Avenue. Blakeley carries Oklahoma State Highway 17, which has its eastern terminus at Business US-81. The business route continues north on Rush Street before angling to the northwest to rejoin mainline US-81.

Business US-81 in Rush Springs is signed with a US-81 shield with a small "B" appended after the number. This method of signing business routes is unusual for Oklahoma.

Business US-81 was originally part of mainline US-81. On May 10, 1971, US-81 was relocated to run west of town, and Business US-81 was designated along the old alignment.[8]

Business US-81 in Kansas is in McPherson. This route is 6 miles (9.7 km) long. It begins at the intersection of I-135, US-81, and US-56 east of McPherson. It goes west on Kansas Ave. for about two miles (3 km) in a concurrency with US-56 and turns south on Main Street for 2 miles (3.2 km), passing Central Christian College and National Cooperative Refinery Association. At K-61, it exits east in a 2 miles (3.2 km) "wrong-way" concurrency with K-61 before ending at I-135 and US-81 southeast of McPherson.

BUS US-81 in McPherson first appeared on the Kansas Department of Transportation Map in 1970 when Interstate 35W (now Interstate 135) was completed between McPherson and Salina.[10]

Former Business US-81 in Lindsborg began at the intersection of Interstate 135, US-81, and K-4 north of Lindsborg on an older routing of US-81. It shared a 4 miles (6.4 km) concurrency with K-4, which turns to the west in south Lindsborg. At this junction, it went for another mile south before turning east on Smoky Valley Road, ending 3 miles (4.8 km) later at I-135 and US-81. This BUS US-81 had a total length of 8 miles (13 km).

The Lindsborg business loop first appeared in 1970, at the same time as the McPherson loop.[10]

It starts off of I-29/US-81 at the 32nd Avenue Exit were it travels east on 32nd Avenue to Washington Street S and Follows Washington Street all the way back to I-29